Regulars / The Andy Thomas-Emans column | 37The Andy Thomas-Emans column Closing the fexo-digital gapA new generation of high-speed digital presses is closing the speed and productivity gap with fexonew generation of digital presses operating at speeds of “There remains a close synergy 100m/min (328ft/min) and upwards is closing the speed and productivity gap with fexography and changing the way A between digital and fexo/we view the conventional-digital equation. During recent open houses at Bobst, HP Indigo and Durst, a conventional technology, with new generation of digital presses were demonstrated reaching new levels of productivity broadly comparable with narrow web advances in conventional fexography in real world operation.technology automation refected At its Expo Label event Durst showed the Tau RSCi, a 510mm-wide (20in) UV inkjet press printing at 100m/min in directly in the productivity of the CMYK+ mode. Adding digital white takes the speed down to 52m/min, but the press was also equipped with a UV fexo station before digital press”the digital print unit which could be used to print a frst down white at full press speed. A second fexo unit after the digital print station would typically be used for a varnish. and converting modules. A modular architecture allows customers On a 510mm web width at those speeds, the productivity of to confgure the machine from a digital-only version to a highly the Tau RSCi press certainly matches narrow web fexography at customized confguration.real-world speeds, but a major obstacle to longer UV inkjet runs has So, what does this tell us about the changing balance between been the additional cost of the ink compared to UV fexo, variously fexography and digital label printing? estimated at between two-to-three times as much. Firstly, it seems clear that the days of the ‘entry-level’ fexo Durst has sought to address this with its Save Ink mode, press – typically 8-color, shaft driven, no value-adding units – are which uses some impressive color management algorithms to numbered. There is a very large legacy installation base of such re-formulate the colors required to make up an image to produce machines, and their one-to-one replacements are quite likely to ink savings up to 12 percent while staying within a delta 2 of the be digital. original. In practice the two images are virtually indistinguishable. But one should not write off fexography. Flexo technology The fnal part of the high productivity jigsaw was provided has itself undergone a revolution in the last ten years. Digital by A B Graphic, which demonstrated a 530mm-wide Digicon control of conventional print and converting operations has unit equipped with the Fast Track high speed semi-rotary opened up completely new possibilities for shorter runs with die-cutting unit capable of operating at speeds up to 150m/ minimal waste and a high level of automation and autonomy min. The Digicon can be used in-line with the Tau RSCi, although during the print process.a near-line confguration remains the preferred approach for Indeed, to achieve their high levels of productivity all the digital maximum fexibility. presses mentioned above still rely in different ways on advanced, At the HP VIP event the V12 press was demonstrated publicly automated conventional technology to convert the digitally printed for the frst time. The press at the HP technology campus is still label. Whether they are in-line hybrid systems like the Bobst Digital an alpha development machine, with the frst beta contracts now Master, or whether they use ABG’s converting technology, there being signed. But the potential for HP Indigo’s new rotary blanket remains a close synergy between digital and fexo/conventional architecture was immediately obvious, with the press reaching technology, with advances in conventional technology automation speeds up to 120m/min in 4-color mode on a paper substrate. refected directly in the productivity of the digital press.The V12 can print at full speed in up to six colors, with any In addition, the cost of digital inks will always be more than UV additional colors halving the speed. But as CMYK work probably fexo inks – although clever systems like the Durst Save Ink are accounts for upwards of 95 percent of the average label printer’s seeking to reduce the gap. The answer could be a UV fexo station workload, this is unlikely to be a signifcant limitation. used to lay down the color with the highest coverage, greatly ABG is currently developing a converting line to match the increasing the run length economically viable with a high-speed V12, including a butt splicer for greater productivity. Again, the digital press.confguration is much more likely to be near-line than in-line, So digital and (digitally-controlled) conventional technology will although that possibility defnitely exists. continue to work together to greatly increase the productivity of Bobst has taken an all-in-one approach with the launch of its the high-speed digital press. new high productivity digital press series. The 510mm-wide Digital Master prints at speeds up to 100m/min in up to six colors with For more Andy Thomas-Emans columns, go to printing, embellishment and cutting in a single pass. The press is www.labelsandlabeling.com/contributors/andy-thomasfully modular and incorporates Bobst’s own highly automated fexo Apr - Jun 2022